(1) Field of the Invention
Exemplary embodiments of the present invention relate to a touch substrate and a method of manufacturing the touch substrate. More particularly, exemplary embodiments of the present invention relate to a touch substrate including a sensing element with improved sensitivity and a method of manufacturing the touch substrate.
(2) Description of the Related Art
Generally, a liquid crystal display (“LCD”) panel includes a first substrate on which a thin film transistor is formed to drive a pixel area, a second substrate disposed opposite to the first substrate and a liquid crystal layer disposed between the first substrate and the second substrate.
The LCD panel may function as a touch panel operated by an external touch. In a conventional LCD touch panel, the second substrate of the LCD panel may include a sensing element and a switching element that controls the sensing element. When the LCD panel is touched, the sensing element absorbs an incident light having a wavelength within a predetermined wavelength range to generate a photo current. A central processing unit connected to the LCD panel may determine a touch position using the photo current and a dark current of the sensing element which is determined before the incident light is absorbed.
The sensing element generally has electrical characteristics different from the switching element. The switching element typically controls turn-on and turn-off using a gate signal. In contrast, the sensing element of the LCD panel generates the photo current, so the sensing element may have a high sensitivity for the incident light. To improve the sensitivity of the sensing element, a size of an active pattern that receives the incident light may be substantially increased, or a thickness of the active pattern may be substantially increased. However, when the size of the active pattern is increased, the number of the sensing element disposed on the touch panel may be substantially decreased. In addition, when the thickness of the active pattern is increased, processing time may be substantially increased, and a base substrate may be bent due to a high stress.